This invention relates to cable insulation stripping tools. More particularly, it relates to insulation stripping tools for coaxial cable.
With the phenomenal growth of cable television, the use of coaxial cable has also grown accordingly. As shown in FIG. 1, coaxial cable 10 generally is constructed with a single inner copper conductor 12 having an inner insulation 14, normally of a formed plastic material such as polypropylene foam surrounding the conductor, and a very thin aluminum ground shield 15 surrounding the inner insulation. A tough metal braid 16 surrounds the shield in order to protect the shield and to provide further shielding for the inner conductor. The braid is normally made of a large number of thin wires twisted together along the length of the cable. The cable further includes an outer insulation or jacket 18 which is normally made of polyethylene.
As with all electrical cables, in order to terminate the end of the cable to an electrical connector, the end of the cable must be stripped down to the inner conductor. With ordinary cable, which is normally an electrical conductor surrounded by insulation, stripping the insulation from the conductor does not present much of a problem. However due to the complex structure of coaxial cable, difficulties have been encountered.
One of the major problems occurs because the stripper blade is often used to cut through the braid while also stripping the insulation. The blade becomes dull because of the tough metal braid, thereby necessitating replacement of the blade. This stripping technique has been found to cause the braid to come into contact with the conductor, resulting in short circuits and scoring of the conductor.
One of the leading coaxial cable stripping device products on the market today is called The Coaxial Cable Peeler. The Coaxial Cable Peeler utilizes two blades which are offset from one another. The first blade is used to cut through the outer insulation, the braid and the shield, and the second blade is used to cut through the outer insulation only. The Cable Peeler has the drawbacks set forth above.
The following U.S. Patents show cable strippers which utilize a single specially made blade: U.S. Pat. Nos. 4,594,029 issued to Michael; 4,379,665 issued to Hendershot; 4,729,268 issued to Morrow; 4,426,778 issued to Christie; 4,317,279 issued to Smith; 4,203,333 issued to Campari; 4,112,791 issued to Wiener; and 4,116,092 issued to Wheeler. U.S. Pat. No. 4,366,619 issued to Brieganski shows a cable stripper which utilizes three separate blades for stripping the outer insulation, the braid, and the inner insulation. Each blade is separately adjusted. Brieganski also uses specially made blades.